606 research outputs found

    Control of Synchrotron Radiation Effects During Recirculation With Bunch Compression

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    Studies of beam quality preservation during recirculation * have been extended to generate a design of a compact arc providing bunch compression with positive momentum compaction ** and control of both incoherent and coherent synchrotron radiation (ISR and CSR) effects using the optics balance methods of diMitri et al.***. In addition, the arc/compressor generates very little micro-bunching gain. We detail the beam dynamical basis for the design, discuss the design process, give an example solution, and provide simulations of ISR and CSR effects. Reference will be made to a complete analysis of micro-bunching effects ****

    Portfolio Vol. IV N 4

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    Wager, Dick. Collective Bargaining. Prose. 3-5. Raymond, Toby. Lochinvar Rides Again. Poetry. 6. Wyman, John. Lily of the Alley. Prose. 8-9. Benson, Virginia. Lost Cause. Prose. 10. Collins, Peg. The Curtain Falls. Prose. 11. Dorsey, Ann. Jack. Picture. 12. Sulke, Jim. Old Pete. Picture. 12. Myers, Sue. Jerry. Picture. 12. Rosenthal, Joan. Canadian Farmhouse. Picture. 13. Deeds, Ed. Mirror Lake. Picture. 13. Peters, Doris. Trees. Picture. 13. Seagrave, Leslie. Chinese Coins. Poetry. 14. White, Molly. Thoughts in the Rain. Poetry. 14. Smith, Duke. Keeping the Records Straight. Prose. 15. Stocker, Ed. Joe. Prose. 16-17. Saunders, John. Seven Year\u27s Luck. Prose. 19-22

    Right Hemisphere Partial Complex Seizures: Mania, Hallucinations, and Speech Disturbances During Ictal Events

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    A patient with right hemisphere complex partial seizures exhibited extreme emotional lability resembling mania, neologisms resembling those found in fluent aphasia, and hallucinations during ictal periods. The electroencephalographic and clinical findings in this case suggest that cortical and subcortical structures of the right hemisphere may play a role in mediating the expression of language content. RÉSUMÉ Chez un patient prÉsentant des crises partielles complexes de l'hÉmisphÈre droit, nous avons observÉ pendant les crises une labilitÉÉmotionnelle Évoquant le diagnostic de manie. des nÉologismes ressemblant À ceux de l'aphasie de Wernicke et des hallucinations. Nos constatation EEG et cliniques suggÈrent que les structures corticales et sous-corticales de l'hÉmisphÈre droit peuvent jouer un rÔle dans la mÉdiation de l'expression du contenu linguistique. RESUMEN Un paciente con ataques parciales complejos originados en el hemisferio derecho mostrÓ una labilidad emocional extrema semejante a la mania, neologismos comparables a los que se encuentran en la afasia fluida y alucinaciones durante los perÍodos ictales. Los hallazgos clÍnicos y del EEG en este caso sugieren que estructuras corticales y subcorticales del hemisferio derecho pueden jugar un papel en la funciÓn del contenido del lenguaje expresivo.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66016/1/j.1528-1157.1988.tb05093.x.pd

    Perturbation theory for the one-dimensional trapping reaction

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    We consider the survival probability of a particle in the presence of a finite number of diffusing traps in one dimension. Since the general solution for this quantity is not known when the number of traps is greater than two, we devise a perturbation series expansion in the diffusion constant of the particle. We calculate the persistence exponent associated with the particle's survival probability to second order and find that it is characterised by the asymmetry in the number of traps initially positioned on each side of the particle.Comment: 18 pages, no figures. Uses IOP Latex clas

    Childhood Incident Asthma and Traffic-Related Air Pollution at Home and School

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    Background: Traffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. However, there has been little study of effects of traffic exposure at school on new-onset asthma. Objectives: We evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Methods: Parent-reported physician diagnosis of new-onset asthma (n = 120) was identified during 3 years of follow-up of a cohort of 2,497 kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. We assessed traffic-related pollution exposure based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. Hazard ratios (HRs) for new-onset asthma were scaled to the range of ambient central site pollutants and to the residential interquartile range for each traffic exposure metric. Results: Asthma risk increased with modeled traffic-related pollution exposure from roadways near homes [HR 1.51; 95% confidence interval (CI), 1.25-1.82] and near schools (HR 1.45; 95% CI, 1.06-1.98). Ambient NO2 measured at a central site in each community was also associated with increased risk (HR 2.18; 95% CI, 1.18-4.01). In models with both NO2 and modeled traffic exposures, there were independent associations of asthma with traffic-related pollution at school and home, whereas the estimate for NO2 was attenuated (HR 1.37; 95% CI, 0.69-2.71). Conclusions: Traffic-related pollution exposure at school and homes may both contribute to the development of asthma. Editor's SummaryTraffic-related air pollution has been associated with adverse cardiorespiratory effects, including increased asthma prevalence. McConnell et al. (p. 1021) evaluated the relationship of new-onset asthma with traffic-related pollution near homes and schools. Parent-reported physician diagnosis of new-onset asthma was identified during 3 years of follow-up of a cohort of kindergarten and first-grade children who were asthma- and wheezing-free at study entry into the Southern California Children's Health Study. Traffic-related pollution exposure was assessed based on a line source dispersion model of traffic volume, distance from home and school, and local meteorology. Regional ambient ozone, nitrogen dioxide (NO2), and particulate matter were measured continuously at one central site monitor in each of 13 study communities. The authors report an increase in asthma risk with modeled traffic-related pollution exposure from roadways near homes and schools. Ambient NO2 was also associated with increased risk. Models that included both NO2 and modeled traffic exposures suggested independent associations of asthma with traffic-related pollution at school and at home, whereas the estimate for NO2 was attenuated. The authors conclude that traffic-related pollution exposure at school and home may both contribute to the development of asthma

    Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques

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    race metals (Cd, Cr, Cu, Ni and Pb) concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria). The degree of contamination was assessed using the individual contamination factors (ICF) and global contamination factor (GCF). Multivariate statistical approaches including principal component analysis (PCA), cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources

    Analysis of human meiotic recombination events with a parent-sibling tracing approach

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    <p>Abstract</p> <p>Background</p> <p>Meiotic recombination ensures that each child inherits distinct genetic materials from each parent, but the distribution of crossovers along meiotic chromosomes remains difficult to identify. In this study, we developed a parent-sibling tracing (PST) approach from previously reported methods to identify meiotic crossover sites of GEO GSE6754 data set. This approach requires only the single nucleotide polymorphism (SNP) data of the pedigrees of both parents and at least two of children.</p> <p>Results</p> <p>Compared to other SNP-based algorithms (identity by descent or pediSNP), fewer uninformative SNPs were derived with the use of PST. Analysis of a GEO GSE6754 data set containing 2,145 maternal and paternal meiotic events revealed that the pattern and distribution of paternal and maternal recombination sites vary along the chromosomes. Lower crossover rates near the centromeres were more prominent in males than in females. Based on analysis of repetitive sequences, we also showed that recombination hotspots are positively correlated with SINE/MIR repetitive elements and negatively correlated with LINE/L1 elements. The number of meiotic recombination events was positively correlated with the number of shorter tandem repeat sequences.</p> <p>Conclusions</p> <p>The advantages of the PST approach include the ability to use only two-generation pedigrees with two siblings and the ability to perform gender-specific analyses of repetitive elements and tandem repeat sequences while including fewer uninformative SNP regions in the results.</p

    The Atacama Cosmology Telescope: Sunyaev Zel'dovich Selected Galaxy Clusters at 148 GHz in the 2008 Survey

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    We report on twenty-three clusters detected blindly as Sunyaev-Zel'dovich (SZ) decrements in a 148 GHz, 455 square-degree map of the southern sky made with data from the Atacama Cosmology Telescope 2008 observing season. All SZ detections announced in this work have confirmed optical counterparts. Ten of the clusters are new discoveries. One newly discovered cluster, ACT-CL J0102-4915, with a redshift of 0.75 (photometric), has an SZ decrement comparable to the most massive systems at lower redshifts. Simulations of the cluster recovery method reproduce the sample purity measured by optical follow-up. In particular, for clusters detected with a signal-to-noise ratio greater than six, simulations are consistent with optical follow-up that demonstrated this subsample is 100% pure. The simulations further imply that the total sample is 80% complete for clusters with mass in excess of 6x10^14 solar masses referenced to the cluster volume characterized by five hundred times the critical density. The Compton y -- X-ray luminosity mass comparison for the eleven best detected clusters visually agrees with both self-similar and non-adiabatic, simulation-derived scaling laws.Comment: 13 pages, 7 figures, Accepted for publication in Ap
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